stamar Posted December 3, 2012 Share Posted December 3, 2012 I'm positive I've expplained to. You a few times now my laptop uses a lot more power than yours does. Not all laptops use the same aamount of power. My laptop is an asus g72 a gamer model from a couple years ago. There is no point comparing the run time if you think all laptops use thee same ammount of power. Really there's no point in telling you this again actually, this clicks instantly or it never will. Quote Link to comment Share on other sites More sharing options...
stamar Posted December 3, 2012 Share Posted December 3, 2012 If there is someone who has a laptop they can leave on 24 hours a day with one house battery show us how that is done. My laptop runs on battery about an hour maybe, for a single house batery it really could only be used for a couple hours and then I would need to drive at least 4 hours or plug in... not a daily thing unless you were traveling. I'm pretty sure that a lower power laptop uses about a. Quarter as much power. So multiply my estimate by four. But there's different laptops I suppose there might be one that workks with the stock toyhome set up. I don't believe there is reallyy a laptop that could stay on 24 hours a day without a generator or a larger solar panel but id be interested in someone who is a fulltimer with real eexperience..... Quote Link to comment Share on other sites More sharing options...
stamar Posted December 3, 2012 Share Posted December 3, 2012 That's a good point about comparing the amp hours. But what it shows is there just is not comparison in the amp hours of a house battery and a laptop battery If it literally takes 50 amp hours to power my laptop for 2:5 hours from the house battery and on the other hand it takes two laptop batteries rated at a 5 aamp hours to cover the same amount of time, Comparing those two numbers is obviously barking up the wrong tree. Quote Link to comment Share on other sites More sharing options...
stamar Posted December 3, 2012 Share Posted December 3, 2012 I'm using a 115 hour deep cycle size 27 battery btw brand new. When I started off my journey 2 mmonths ago I thought I would be using my laptop in my rv everyday as well but it went through about 2 days before that idea died, I. Even plugged in the converter box to a land line while I was doing it one night and iii still ran the battery to zero in 8 hours.( this was a bad idea but I ran the laptop off the inverter instead of literally plugging it in to the landline) So I started to improve my rv with all led lights a solar panel and I'm getting a laptop with about one quarter the power draw. Three different improvements on something that started out a complete failure. The larger battery doesn't really do me anyy good for a everyday use I still need to replace the power going out everyday. But I'm getting a 2nd battery too for apx 200 amp hours. Id liek to leave my laptop on 24 hours but 12 will cut it Quote Link to comment Share on other sites More sharing options...
stamar Posted December 3, 2012 Share Posted December 3, 2012 Some of the newer Sony Viao laptops have an optional secondary battery that snaps onto the bottom of the laptop case. That battery is a relatively flat panel same size as the bottom of the laptop. Those Sony's have an 6 hour battery life to start with and with the secondary battery you get up to 14 to 16 hours of battery life. But you will pay a good sized price for that kind of performance. The new Intel i 17 dash three processors are made for running on less energy than earlier processors. You opted for a fuel efficient motorhome, now you had better opt for a fuel efficient laptop. Not sure why that connection does not seem to make sense to people. Your motor home is not capable of turning a fuel guzzling old laptop into an energy efficient one... Ya well that's a different idea that can help which is to buy a business laptop with its own battery. A laptop operates differently on its own battery than plugged in and its not useful to me to be onlyy on its own battery. But having a huge internal battery for the laptop will help for instance if the lapt op can makke it on the house battery for 12 and its own battery for 12 that works, Iim not usually into the sony laptops for that but more a thinkpad or a dell lattitude. The intel cpus that use the least power are calle u series. I3 i5 i7. The regular cpus use the same amount of power laptops did 5 years ago, there has actually been no improvement in this area. Quote Link to comment Share on other sites More sharing options...
zero Posted December 3, 2012 Share Posted December 3, 2012 . There is no point comparing the run time if you think all laptops use thee same ammount of power. Really there's no point in telling you this again actually, this clicks instantly or it never will. I never suggested that all lap-tops use the same power. I'm also well aware that any specific lap-top has different power needs depending on what is actually being done with it and what mode you are running it in. Reading files uses less power then doing video processing, conversion, or burning DVDs. I can't comment on games because I don't play games on computers. I didn't even like Pac-Man which didn't need much power. As to my relevance? There have been many comments about generic lap-lops in general and not just one specific use like your's. So yes, I can easily run my lap-top for 20 hours on my house batteries - but why would I? I don't run any computers 20 hours a day in my house either. It all boils down to fairly simple math as long as battery and inverter loss is figured in. If a lap-top comes factory equipped with a 6 amp-hour battery and can run 2 hours on it - then a battery 20X its size is going to power it near 20X as long. Even if you factor in 20% inverter and battery loss - and a discharge stopping at 50% - that still comes to 15 hours of run time. As to your specific lap-top and particular use? The math for you is no different but I don't know what your average draw is per hour. On the generic level - having a long run time is not a problem. At your level - maybe. Quote Link to comment Share on other sites More sharing options...
83 SunRader Posted December 3, 2012 Share Posted December 3, 2012 Please remember I'm new to the RV thing. How are you all plugging your laptop into the DC? My outlets don't work unless I'm plugged into an electrical source. By the way this would be a good thread on it's own. Quote Link to comment Share on other sites More sharing options...
zero Posted December 3, 2012 Share Posted December 3, 2012 That's a good point about comparing the amp hours. But what it shows is there just is not comparison in the amp hours of a house battery and a laptop battery If it literally takes 50 amp hours to power my laptop for 2:5 hours from the house battery and on the other hand it takes two laptop batteries rated at a 5 amp hours to cover the same amount of time, Comparing those two numbers is obviously barking up the wrong tree. When running off the RV battery, are you doing it with DC to DC, or are you using an inverter and going DC to AC to DC? The only major difference between a lead-acid RV battery and your lap-top is the RV battery should only be run down to 1/2 charge, whereas the laptop battery can be run until it craps out. A 5 amp-hour laptop battery is an equivalent to a 10-20 amp-hour lead-acid RV battery. My Duracell portable power-pack only has a 26 amp-hour lead-acid battery in it and it can run any of our laptops about twice as long as they can be run on their own batteries. My RV batteries total 225 amp-hours and we've had rainy days when we sat inside all day and evening running a dorm-type AC refrigerator, a 19" or 32" LCD TV, DVD player, lights, water pump, fans, etc. and that's with dual inverters (1500 watt and 2000 watt) that add loss. Never ran our batteries down to 11 volts yet. Quote Link to comment Share on other sites More sharing options...
zero Posted December 3, 2012 Share Posted December 3, 2012 Please remember I'm new to the RV thing. How are you all plugging your laptop into the DC? My outlets don't work unless I'm plugged into an electrical source. By the way this would be a good thread on it's own. All you need is a DC to DC power supply or cord. You just have to match whatever voltage your computer uses. Many are 10-11 volts DC and they can be run with no converter. if you have a computer that runs higher then 12 volts -then you need a DC to DC power supply. The standard 12 volt power port is only capable of 20 amps at 12 volts DC, i.e around 200 watts. All my laptops can run on much less then that. If your's needs more - then you need a DC cable to go direct to your RV battery or converter. Quote Link to comment Share on other sites More sharing options...
zero Posted December 3, 2012 Share Posted December 3, 2012 Please remember I'm new to the RV thing. How are you all plugging your laptop into the DC? My outlets don't work unless I'm plugged into an electrical source. By the way this would be a good thread on it's own. Here are a few alternatives. One is the DC to DC converter that steps up the 12 volts from your RV and makes the output to match your laptop. Many newer laptops need 18 volts. http://www.powerstream.com/ADC.htm Another very handy way to run a lap-top while camping, RVing, etc. is use something like the Duracell Powerpack 600. I have two and these things greatly exceeded my expectations. My wife is homeschooling our "last" little kid. So, she brings the lap-top everywhere since it's her mobile text book. Out in the woodss, when we go fishing, driving and camping, etc. Weighs around 30 lbs. Has a 28 AH battery and a 600 watt inverter with two AC outlets and one 12 volt DC outlet. It easily runs any of our laptops for 2-4 hours depending how we're using them. Also runs a 19" LCD TV and DVD player well enough to watch any full length movie. You can recharge it by plugging into the truck power outlet or cigarette lighter - or with AC. If you shop around then can be bought for $150. Quote Link to comment Share on other sites More sharing options...
83 SunRader Posted December 3, 2012 Share Posted December 3, 2012 Thank you all for your replys! Very helpful. Quote Link to comment Share on other sites More sharing options...
stamar Posted December 3, 2012 Share Posted December 3, 2012 yes im going dc to ac to dc. for that reason comparing the amp hours of your rv battery to the amp hours of the laptops internal battery ( which is also putting out 11 volts vs 19 and operates the laptop on a different internal line) is totally worthless. Quote Link to comment Share on other sites More sharing options...
stamar Posted December 3, 2012 Share Posted December 3, 2012 unfortunately what you linked is a dc to ac to dc converter. its called a dc to dc converter maybe but thats not what it is. I dont even want to get into this headache discussion lol but that is not what you think it is. There is definitely such thing as a dc to dc converter. Thats not one though. the real thing is super cheap. For sale from a us vendor try dell.com no links currently but its the right idea just the wrong product. Quote Link to comment Share on other sites More sharing options...
zero Posted December 4, 2012 Share Posted December 4, 2012 unfortunately what you linked is a dc to ac to dc converter. its called a dc to dc converter maybe but thats not what it is. I dont even want to get into this headache discussion lol but that is not what you think it is. There is definitely such thing as a dc to dc converter. Thats not one though. the real thing is super cheap. For sale from a us vendor try dell.com no links currently but its the right idea just the wrong product. You've lost me on this one. Seems you are not reading very closely or maybe not at all? The Power Stream sells many DC to DC converter. They work with 10.5 to 15 volts DC via a cigarette lighter or power port on the input and put out 18 volts DC (if you order an 18 volt unit). Power Stream also sells AC to DC converter but that's not what I've been referring to. The link I posted clearly shows both. Why you choose to just look at the AC ones, I don't know? You can scroll down and find many specifically made for certain Laptop brands and models. E.g., for my Compaq - they have .. High Reliabilty Automobile to Laptop DC/DC Converter for CIMV, Compaq, Comp USA and CTX -- Retail Sales http://www.powerstream.com/ADC-Compaq.htm Quote Link to comment Share on other sites More sharing options...
zero Posted December 4, 2012 Share Posted December 4, 2012 yes im going dc to ac to dc. for that reason comparing the amp hours of your rv battery to the amp hours of the laptops internal battery ( which is also putting out 11 volts vs 19 and operates the laptop on a different internal line) is totally worthless. Saying the data Is "totally worthless" is hyperbole. All the data is useful if you calculate correctly. Watts is watts no matter what voltage we are discussing. The factors to be figured in are - inverter loss, battery loss. battery safe run-down capacity,etc. All of which I've already mentioned. If someone is not sure how to do the math, then just use an inverter-battery-loss calculator. They are all over the Net. That are often used when planning solar homes that run off of battery banks and have inverters and AC applicances. Quote Link to comment Share on other sites More sharing options...
zero Posted December 4, 2012 Share Posted December 4, 2012 unfortunately what you linked is a dc to ac to dc converter. its called a dc to dc converter maybe but thats not what it is. I dont even want to get into this headache discussion lol but that is not what you think it is. There is definitely such thing as a dc to dc converter. Thats not one though. the real thing is super cheap. For sale from a us vendor try dell.com no links currently but its the right idea just the wrong product. I still have no idea why you claim these DC to DC converters are NOT what the specs say they are?? As to Dell and cheap converters - not all lap-tops need voltage "step-up." If a truck power-port is 12-14 volts and a lap-top runs on 12 volts or less - then a simple voltage converter or reducer can be used. But if the truck is 12-14 volts and the lap-top is 18 to 24 volts - then a DC to DC converter is needed that has a step-up transformer inside. This one is listed for many Asus laptops: More specs for note – DC to DC convetrters . . Quote Link to comment Share on other sites More sharing options...
stamar Posted December 4, 2012 Share Posted December 4, 2012 Ya you can clearly see its a dc to ac to dc converter it has the power box. They can call it a dc to dc converter because that's what it does in the end. It has the ac to dc box just likkkke a laptop does. The problems definitely not in what I don't. Read lol its just that I've pretty clearly already looked all of this stuff up. Many of the regulars I'm sure have as well. You can find an actualy dc to dc converter on ebaay and various other sources. At this point all of the car converters like the one you're showing are dc to ac to dc inverters. You can't miss it it has a ac to dc rectangle box in it.... Quote Link to comment Share on other sites More sharing options...
stamar Posted December 4, 2012 Share Posted December 4, 2012 Ya you can clearly see its a dc to ac to dc converter it has the power box. They can call it a dc to dc converter because that's what it does in the end. It has the ac to dc box just likkkke a laptop does. It shouldn't take you more than iq about ... 90 to look at the ac to dc plug in they sell ok, and then look at the dc to dc one the sell and then compute its the same thing. Same size lol. It ends with a box that converts ac to dc that's hat the rectangle is. The problems definitely not in what I don't. Read lol its just that I've pretty clearly already looked all of this stuff up. Many of the regulars I'm sure have as well. You can find an actualy dc to dc converter on ebaay and various other sources. At this point all of the car converters like the one you're showing are dc to ac to dc inverters. You can't miss it it has a ac to dc rectangle box in it.... Quote Link to comment Share on other sites More sharing options...
stamar Posted December 4, 2012 Share Posted December 4, 2012 The reason they sell them like that is that its a way to raise up the voltage. Its not what you are looking for for max efficiency of a 12 volt system you need some more research. If all you do is type dc to dc inverter into google theres plenty of people ready to take your money. And a lot of it that thing is even expensive. Quote Link to comment Share on other sites More sharing options...
stamar Posted December 4, 2012 Share Posted December 4, 2012 Today is definitely a day where we all should get in touch with how assume makes an behind out of Well we all have days like that. But pparticularly if your assumption is based on an advertising page its filled with stuff to mislead you. Thank gosh you have other people to run your assumptions by or you'd make incorrect decisions and purchases and maybe even steer someone wrong into doing the same thing Whew What that is is a inverter and an ac box. The reason I'm positive is because I've looked at tons of them. Quote Link to comment Share on other sites More sharing options...
stamar Posted December 4, 2012 Share Posted December 4, 2012 Ya they're allowed to call a dc to ac to dc inverter a dc to dc inverter to sell to suckers Quote Link to comment Share on other sites More sharing options...
stamar Posted December 5, 2012 Share Posted December 5, 2012 http://www.ebay.com/...=item3a74869f62 heres something that should work ive got a list of devices to try out in my laptop solar power project. I asked my buddy who is a electrical engineering student to show me whats involved. Ive seen people make them from simple step ups that are part of a stereo installation kit. So the parts are common as hell but the retail packaging of this device is blockaded in the us. 99.999999% of all things sold with the name laptop car charger are dc to ac to dc inverters essentially the same as plugging into a small cigarette lighter inverter and plugging your own power supply into it. They can be clever about packaging but if they literally show you the ac to dc powerbrick, you know the rectangular ac to dc powerbrick that comes with all laptops, you have a good idea what youre getting is a dc to ac to dc converter. not what you are looking for if it is what youre looking for at least get it on ebay or amazon for 12$ if there is someone other than jd whos confused please pm me so that whatever this thread is about can continue. Quote Link to comment Share on other sites More sharing options...
zero Posted December 5, 2012 Share Posted December 5, 2012 Ya you can clearly see its a dc to ac to dc converter it has the power box. They can call it a dc to dc converter because that's what it does in the end. It has the ac to dc box just likkkke a laptop does. It shouldn't take you more than iq about ... 90 to look at the ac to dc plug in they sell ok, and then look at the dc to dc one the sell and then compute its the same thing. Same size lol. It ends with a box that converts ac to dc that's hat the rectangle is. The problems definitely not in what I don't. Read lol its just that I've pretty clearly already looked all of this stuff up. Many of the regulars I'm sure have as well. You can find an actualy dc to dc converter on ebaay and various other sources. At this point all of the car converters like the one you're showing are dc to ac to dc inverters. You can't miss it it has a ac to dc rectangle box in it.... A "90" IQ might also lead someone to the conclusion that not all "rectangle" boxes are the same. Another poster asked about powering his lap-top in his RV. I suggeted a DC to DC converter as one good alternative and it is. Not all " rectangle boxes" are the same when it comes to electonics. I also seems we don't agree on the meaning of the word "convert?" Those devices do just as advertised. That take low voltage direct-current on the input side, make it pulse and use two windings with different wind-ratios and put out higher direct-current on the output side. To do so, a step-up transformer is used along with a voltage-regulating circuit and some caps. You condemn something because it has a "box" in it? When you run an AC applicance from an inverter - from batteries - there is loss because an inverter has to step up the voltage from 12 volts all the way up to 120 volts and also - create something like a Hertz-cycle sine-wave that spikes at 150-170 volts at both ends of the waves. Typical efficiency is 85-90%. If you get an inverter to run like voltages - the transformer can be left out, more-or-less. You can buy a tiny inverter that will take 120 volts from a DC battery bank (ten12 volt batteries in series) and then "invert" it to 120 VAC. Not practical in an RV though. The DC to DC converters are called "converters" because they take a given DC voltage and convert it to some other voltage in DC. The "boost converters" like Power Stream sell do exactly that. A pulsating current is created by switching inside the "box." So yes, to step up voltage some reversal of current is needed. The end result is basically the same efficiency as a typical inverter. 85-90%. For simplicity sake - for the guy that asked - sticking a self contained 120 watt DC to DC converter in a cigarette lighter is one easy way to do it. AC (alternating current) is what happens anytime two magnetic fields are passed by each other - as in any generator. Even the old DC generators in cars and trucks back in the 60s were actually making AC current and then custom selecting just the DC pulses via brush placement on the commutator.. A modern alternator also starts out with AC but uses both ends of the waves by using semi-conductors (full wave rectifiers). Similar effect when you take two coils of wire (transformer) and quickly turn the power on and off in one. That's how the DC to DC booster converters work. Also how many hybrid cars work. In a hybrid car - some take a 200 volt battery pack - run it through a DC to DC converter and step it up to 500 volts. Regardless if the presence of a "box" upsets you - the device does exactly as indicated. Quote Link to comment Share on other sites More sharing options...
stamar Posted December 5, 2012 Share Posted December 5, 2012 no it does not. it is a dc to ac to dc converter. it doesnt upset me at all it just shows what it is. a dc to dc device has this basic part as its main component http://www.ebay.com/...=item1e7510cfdc it doesnt really need any sort of ac to dc power brick involved in it. You can spot the powerbrick pretty easily usually, its the ac to dc powerbrick that comes with all laptops, the one that converts ac to dc. If the device has the ac to dc powerbrick as part of its components, theres a good chance what it is is a dc to ac to dc converter. If that is what youre looking for they go for closer to 12$ normally depending on the size. http://www.amazon.com/Genuine-Dell-Family-Travel-Includes/dp/B0040RZNKQ/ref=sr_1_90?ie=UTF8&qid=1354721132&sr=8-90&keywords=dc+to+dc+car+adapter heres something that will hopefully end your confusion. You can see this device actually uses the same ac to dc power brick, regardless of whether you plug in the car adapter or the wall adapter. Thats where you can definitely spot if your car adapter is dc to dc or if its dc to ac to dc. Its the ac to dc power brick. Dont get angry about it just get in touch with what it does. Theres nobody thats confused about it at this point thats a lot of explaining I just did. Quote Link to comment Share on other sites More sharing options...
zero Posted December 5, 2012 Share Posted December 5, 2012 no it does not. it is a dc to ac to dc converter. it doesnt upset me at all it just shows what it is. a dc to dc device has this basic part as its main component http://www.ebay.com/...=item1e7510cfdc it doesnt really need any sort of ac to dc power brick involved in it. You can spot the powerbrick pretty easily usually, its the ac to dc powerbrick that comes with all laptops, the one that converts ac to dc. If the device has the ac to dc powerbrick as part of its components, theres a good chance what it is is a dc to ac to dc converter. If that is what youre looking for they go for closer to 12$ normally depending on the size. The device you've linked to on Ebay probably works by two windings and pulse-width-modulation switching. Not sure but that's what it looks like at a glance. If so -it is still pulsing the current to create a step-up. Such a pulse is alternating current although it's not 120 Hertz Cycle. So what? The reality is -if you size your load to the device - you might achieve 95% efficiency - even with an over-the-counter DC to AC inverter or a DC to DC converter. Otherwise the efficiency is usually lower. You stated . . . 99.999999% of all things sold with the name laptop car charger are dc to ac to dc inverters essentially the same as plugging into a small cigarette lighter inverter and plugging your own power supply into it." That is wrong. When you plug your AC cord from your laptop into a inverter - you've got two "boxes" with 10% loss each. The lap-top power supply and the inverter - I.e., around 20% loss making heat instead of useful power. When you plug your laptop into a DC to DC converter - you've only got the loss of one "box" as you put it. Around 10% loss instead of 20%. The lap-tops 120 watt "heater" box has been eliminated. Quote Link to comment Share on other sites More sharing options...
stamar Posted December 5, 2012 Share Posted December 5, 2012 Ya Im actually in the process of getting the loss amount from a true dc to dc converter because actually my expert friend doesnt know theres nothing simple about its efficiency. it adds a lot of resistance in the wiring distance. A perfect one for the step up non adjustable would be better than anytihng i listed so Im not actually suggesting buying those just giving an example. The correct one is actually way simpler and should be efficient but im not sure what it beats. Somewhere we all got into a discussion of this and there was a lot of disinformation about it unfortunately. but its somewhere here probably in electrical. To build a better laptop converter. When Ive got the right one to buy ill nail this down for you all but im buying one peice at a time. im a horse before the cart person and im not buying one of those until I have my rv set up for solar. looks like jan feb. I can see your point about the two boxes and the one box doing the same thing. But theres no actual data that Ive seen that shows this. It could even be less effecient, the device itself could be made very inneffecient. Its still the same things an inverter and ....an inverter. its possible to use a more effecient ac to dc box than came with the laptop, very easilyt because the ones made for land line plug in are wasteful. theres no real data to look up, consumer testing etc that shows power draw. I think its about the same I guess you could theorize its more effecient its possible. if you can skip that ac to dc box completely, ignore the inverter youll use less power i guarantee. whatever number you think the two devices waste theyre not that close. if you have dc to dc youll lose less power Im sure of that. I dont have an amount that makes me a millionaire in mind. But the loss is not the inverter to ac part its the inverter to dc part thats the big loser. and thats in all of these devices whether its a good one or a bad one. Quote Link to comment Share on other sites More sharing options...
stamar Posted December 5, 2012 Share Posted December 5, 2012 theres another regular user thats trying to power his laptop without an inverter from 12 volts through the battery pack. Quote Link to comment Share on other sites More sharing options...
Derek up North Posted December 5, 2012 Share Posted December 5, 2012 ... my expert friend doesnt know theres nothing simple about its efficiency. Is this the Engineering student? Quote Link to comment Share on other sites More sharing options...
stamar Posted December 5, 2012 Share Posted December 5, 2012 ya his name is mike ruehle here in portland hes going to oregon institute of technology. I ran this idea by him last month and didnt bother to figure out what to buy because i needed to upgrade my charging system. hes actually a certified 12 volt electrical engineer so this is what he would do all day if he was working. I havent talked to him since then about it Ive got to have the set up ready and then i might end up actually buying the parts from industrial source. for what it matters im an industrial machine operator at the moment which requires lots of electrical troubleshooting. but absolutely no engineering. im actually dealing with robotics vacuum bacterial growth... a whole bunch of crap that makes an rv look like a tinker toy. in this setting it never matters what uses less power its about what breaks down less. I have a lot of work experience in machine maintenance but again figuring out the power usage never comes up. Quote Link to comment Share on other sites More sharing options...
Derek up North Posted December 5, 2012 Share Posted December 5, 2012 hes actually a certified 12 volt electrical engineer I've no idea what that is. The closest Google spit out on the 1st page was "MECP certified 12 volt technician". Quote Link to comment Share on other sites More sharing options...
zero Posted December 5, 2012 Share Posted December 5, 2012 theres no real data to look up, consumer testing etc that shows power draw. I think its about the same I guess you could theorize its more effecient its possible. if you can skip that ac to dc box completely, ignore the inverter youll use less power i guarantee. whatever number you think the two devices waste theyre not that close. There is lots of verified data to be had. What do think people do who live off grid on 12 volts or 24 volts DC? Just guess at everything and hope for the best? And yes, a few do and many others read specs and plan. In regard to lap-tops and the power-supplies they come with - there are tons of data out there. They tend to be very inefficient as sold in the USA and Canada. The newer Energy Star 4.0 requirement is for a power supply that is at least 80% efficient and many new ones have failed. So yes - lots of data around and those AC powered supplies that lap-tops come with are often a lot more inefficient then inverters or DC to DC converters. Main problem is many do not "load-sense." They often have 20% loss and that's twice what most inverters and converters have. I'm not going to cite specs unless we are discussing specific units. Inverters in general run 90 % efficient but even that varies with each one depending on how much load is involved. Same goes for DC to DC booster converters. Most average around 90% efficiency. Same goes with just about anything converting electricity via a pulse and two wire-windings. No big secrets here -not even for an engineering student - whatever that is supposed to prove. I have two sons who have their electrical engineering degrees and work as actual engineers for NASA. Does that mean they know everything? No - nor do I and neither does your student friend. I've been working with electronics for over 50 years - as well as heavy equipment and diesel engines. And yeah, I was a student once too as far as college goes. My experience is well -rounded but stuff changes all the time and it takes work to keep up. I have to laugh a bit when you mention someone's IQ. My brother had one of the highest tested IQs in the country - yet he could never even pass a road test to get his driver's license. In fact, he'd be lost figuring out which end of screwdriver to use. IQ for practical purposes doesn't always mean much. Quote Link to comment Share on other sites More sharing options...
stamar Posted December 5, 2012 Share Posted December 5, 2012 yes thats right 12 volt technician. Not an engineer. Hes an engineering student. well its not that often youd talk to someone whos job it is to create 12 volt machinery but its true thats what he does. Ya there could be a general power usage test but theres no actual consumer reports sort of thing kept on it as opposed to just the electronics general reliability. Im not actually interested in doing any testing in my set up im more interested in buying it based on the correct info and then never thinking about it again. but theres a possibility when i get my new laptop im going to test the relative power lost with mike to see whats really disapearing. i have a feeling the monster power supply in my asus just hemorages power its actually a replacement from amazon called pwr+ Quote Link to comment Share on other sites More sharing options...
stamar Posted December 5, 2012 Share Posted December 5, 2012 Ya I definitely reviewed our disagreement....and im more positive now everything I said was correct. I guess anyone out there could be thomas edison its just how careful they are in verifying and looking something up. first you say its a dc to dc converter because it says it is, and then just because its a box doesnt it make it an ac inverter then whatever it still might use a lot less power... Its the fun of friendly chat I just actually have a lot of data that says dont buy what jd listed its an expensive thing with probably no benifits or unverified benefits based on im not sure what. some secret document sent among the solar panel house owners........ ;o) buy something way cheaper. im not interested in arguing i just like to have things straight for people who want a correct set up, the things to buy. Nobody has to be as detail oriented as me but I always get a lot of feedback and thanks from people who are looking for correct thing to buy. i just naturally shop in a deadly serious manner for anything from food to auto parts and i share with whoever is around what I find. Quote Link to comment Share on other sites More sharing options...
Derek up North Posted December 5, 2012 Share Posted December 5, 2012 Perhaps you could 'direct link' your data? Quote Link to comment Share on other sites More sharing options...
stamar Posted December 5, 2012 Share Posted December 5, 2012 i definitely already did heres an example of something thats exactly the same its a univeral car charger http://www.amazon.co...top car charger http://www.buy.com/p...ingId=154637416 or this theres thousands of them for sale.... some very cheap. I can find them for under 5$ non universal if you give me your laptop model number. its dc to ac to dc heres an example of an actual dc to dc http://www.ebay.com/...=item5aec15ed8b which is closer to the theory involved of skipping the ac to dc inverter. an advertised 94% effeciency rate untested. The link jd shared is selling basically what i showed you is the same old car inverter calling it dc to dc, and charging a lot. If theres someone out there that cant see this just pm me. Theres no way anyone who is reading missed that. Quote Link to comment Share on other sites More sharing options...
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